Covert Channel Analysis
LOW MODERATE HIGHRequirements NIST SOURCE
Requirement Context
This element is part of SC-31 — Covert Channel Analysis. See the Assessment section below for the related SP 800-53A examine/interview/test procedures. No engineering interpretation has been authored for this control yet.
Requirement Context
This element is part of SC-31 — Covert Channel Analysis. See the Assessment section below for the related SP 800-53A examine/interview/test procedures. No engineering interpretation has been authored for this control yet.
Discussion (NIST Supplemental Guidance)
Developers are in the best position to identify potential areas within systems that might lead to covert channels. Covert channel analysis is a meaningful activity when there is the potential for unauthorized information flows across security domains, such as in the case of systems that contain export-controlled information and have connections to external networks (i.e., networks that are not controlled by organizations). Covert channel analysis is also useful for multilevel secure systems, multiple security level systems, and cross-domain systems.
Enhancements NIST SOURCE
SC-31(1) Test Covert Channels for Exploitability LOW MODERATE HIGH
Test a subset of the identified covert channels to determine the channels that are exploitable.
Discussion
None.
SC-31(2) Maximum Bandwidth LOW MODERATE HIGH
Reduce the maximum bandwidth for identified covert [one of: storage; timing] channels to [values].
Discussion
The complete elimination of covert channels, especially covert timing channels, is usually not possible without significant performance impacts.
SC-31(3) Measure Bandwidth in Operational Environments LOW MODERATE HIGH
Measure the bandwidth of [subset of identified covert channels] in the operational environment of the system.
Discussion
Measuring covert channel bandwidth in specified operational environments helps organizations determine how much information can be covertly leaked before such leakage adversely affects mission or business functions. Covert channel bandwidth may be significantly different when measured in settings that are independent of the specific environments of operation, including laboratories or system development environments.
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for SC-31 yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.
Assessment
Assessment Objectives
- one or more of the following PARAMETER VALUES is/are selected: {storage; timing};
- a covert channel analysis is performed to identify those aspects of communications within the system that are potential avenues for covert <SC-31_ODP SELECTED PARAMETER VALUES> channels;
- the maximum bandwidth of those channels is estimated.
Examine
[SELECT FROM: System and communications protection policy; procedures addressing covert channel analysis; system design documentation; system configuration settings and associated documentation; covert channel analysis documentation; system audit records; system security plan; other relevant documents or records].
Interview
[SELECT FROM: System/network administrators; organizational personnel with information security responsibilities; organizational personnel with covert channel analysis responsibilities; system developers/integrators].
Test
[SELECT FROM: Organizational process for conducting covert channel analysis; mechanisms supporting and/or implementing covert channel analysis; mechanisms supporting and/or implementing the capability to estimate the bandwidth of covert channels].
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for SC-31. This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.
Learn more about STIG/CCI integration →Evidence
Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.
Policy
- System and communications protection policy
- system security plan
Configuration
- system design documentation
- system configuration settings and associated documentation
Testing
- Organizational process for conducting covert channel analysis
- mechanisms supporting and/or implementing covert channel analysis
- mechanisms supporting and/or implementing the capability to estimate the bandwidth of covert channels
Other Records
- procedures addressing covert channel analysis
- covert channel analysis documentation
- system audit records
- other relevant documents or records